1. Field of the Invention
This invention relates to apparatus for traversing a magnetic head-loading arm assembly in the form of a pair of loading arms, each having magnetic head assemblies mounted thereon through gimbal springs onto a rotating disc and more particularly to apparatus for traversing a magnetic head-loading arm assembly into position between a pair of spaced rotating discs wherein the gimbal spring magnetic head assemblies are urged by a comb assembly into a position adjacent to the loading arm such that when the magnetic head-loading arm assemblies are positioned in the space between the rotating discs, the comb assembly is moved into a disengage position loading the magnetic heads onto the rotating disks.
2. Field of the Invention
Disc driving apparatus utilizing a plurality of discs stacked one above the other for rotation about the same axis of rotation is well known in the art. Typically, a plurality of magnetic recording and reproducing heads and a magnetic servo head are mounted on a carriage loading arm assembly which is adapted to be actuated lengthwise in a straight-line path along the radii of the rotating magnetic discs. In the known disc drive apparatus, the carriage loading arm assembly includes means for holding the magnetic heads away from the surface of the disc during the loading operation (hereinafter referred to as the "loading position") and, when the carriage loading arm assembly is in position, the magnetic recording heads are disengaged from the carriage loading arm assembly and are permitted to move toward the surface of the rotating magnetic discs (hereinafter referred to as the "disengage position"). Typical of such systems are those offered for sale and sold by IBM Corporation and generally referred to as the 3378 Winchester-type system.
It is also known to the art to provide for a rotary actuated loading mechanism to position the magnetic heads on the disc drive apparatus at an angle relative to the rotating discs. In such apparatus, the magnetic heads are moved along an arc roughly coinciding with the radius of the disc extending across the disk recording area. One such head-loading mechanism for rotary actuation of heads relative to the rotating discs is disclosed in U.S. Pat. No. 4,071,867. The head loading mechanism described in U.S. Pat. No. 4,071,867 includes a pair of hinge-connected cam members having cam surfaces which bear against extending ends of a spring member mounted onto a rotatable elongated arm which supports the recording head. The disc's end of the elongated arm includes a spring member which decidedly engages hinge cam members during the loading operation. The cam members of the head loading mechanism cooperate with an extended end of a spring member so as to hold the magnetic heads away from the surface as they are moved from a position away from the disc pack to a position over the disc surfaces.
It is also known in the art to utilize apparatus for traversing a magnetic head-loading arm assembly along a linear path to load magnetic head-loading arm assemblies onto rotating test discs for testing purposes. Certain of the known magnetic head testing apparatus utilize a cam surface in the form of a contoured knife blade to engage in whole and magnetic heads in a position to avoid contact with the rotating disc surface during loading and unloading operations. The carriage-loading arm assembly had the magnetic heads supported thereon by arcuate shape flexures, and the contact between the camming members and the arcuate shape flexures was not critical, and the engagement there between was controlled by forming a steep slope angle on the edge of the cam members. Such transversing apparatus was utilized for testing carriage loading arm assemblies and the rotating disc apparatus generally referred to as the type 3350 Winchester system.
With the advent of higher density disc-drive apparatus, the size of the magnetic recording and reproducing heads and magnetic servo heads have become smaller and more critical. The gimbal spring magnetic recording and reproducing head assembly construction utilizes a flexure wherein the loading forces placed thereon and the deflection thereof, in terms of gram-loading, become significant.